Carburetor



2 Sheets-Sheet 1 /n ven or Marcelouz'sMemeSsan M. MENNESSON CARBURETORFiled Dec. 9, 1955 June 21, l193s.

JuneZl, 1938. .M MENNESSON 2,121,506

CARBURETOR Filed Dec. 9,\ 1935 2 Sheets-Sheet 2 15 In venian.'Marllouisemesson Patented June 2l, 1938 CARBURETOR Marcel Mennesson,Neuilly-sur-Seine, France;

assgnor to Societe Anonyme Solex, Neuillysur-Seine, France, acorporation of France Application December 9, 1935, Serial No. 53,682

In Belgium January 29, 1935 8 Claims.

particularly concerned with those fdr; aircraft' engines. l

The main object is to produce a carburetor which can operate in allpositions to which the engine to which it is tted is brought, even inthe case where the carburetor is turned through 180 from its normalposition.

A oatless carburetor according to the present invention comprises aspace communicating with the suction pipe of the engine by means of atleast one passage whose effective section is relatively small and withthe free air by means of at least one passage whose section isrelatively large so that the pressure in said space is practicallyindependent of the suction prevailing in said suction pipe and in whichspace the primary mixture of fuel and air is effected, fuel being fed tosaid space from a fuel pump, means for controlling the feed of fuel intosaid space, a throttling member for air or mixture in said suction pipeof the engine, and a rigid connection between said throttling member andthe fuel controlling means.

A further feature consists in providing feed regulating members ofcarburetors of the kind in question with means adapted to prevent asudden opening of the said members and, on the contrary, to impose onthis opening a period which corresponds substantially to the period ofaccelerationof the engine.

Another feature consists in embodying in carbu retors of the kind inquestion, means, independent of the quantity of air admitted in thecarburetor and adapted to correct the richness of the mixture, byvarying the discharge pressure of the fuel pump, said means beingactuated manually or automatically as a function of the momentaryconditions of working such as the quantity of mixture to be fed to theengine or the temperature, density or pressure of atmospheric air,considered separately or together. i

In order that the nature of the invention may be more clearlyunderstood, reference will now be made to the accompanying drawings.

Fig. 1 shows, in vertical diagrammatic section, a carburetor constructedaccording to a rst embodiment of the invention.

Fig. 2 shows, similarly, a carburetor constructed according to a secondembodiment of the invention.

Fig. 3 shows, in elevation (parts in section) an alternative of a partof the embodiment according .to Fig.'2.

In the different embodiments represented there is arranged, outside thesuction pipe I of the engine, a space or chamber 2 which isadvantageously given-a spherical form and of which the wall is supportedby suitable means. Into this chamber there opens, near its central part,an air conduit 3 the section of which may be adjustable or not, asdesired, and which opens into the free air, for example by beingconnected to the said suction pipe in front of the throttlingmember-suchfas the butterfly valve ll--which regulates, as in theordinary way, the degree of opening of the said suction pipe I andconsequently the feed of combustible mixture to the engine, by theintermediary of the means described below.

On the attached drawings there is shown, by way of example, an airconduit 3 in the form of a tube of relatively great transverse sectionand of which the greatest part is substantially parallel to the axis ofthe suction pipe I. Further, the axis of the air pipe is offset somewhatbeyond the theoretical centre of the said chamber 2.

In the chamber I there also opens a conduit 5 for the feed of fuel insuch a Way that the outlet orifice of the said conduit is not-locatedopposite the air conduit 3, the outflow of fuel being effected forexample parallel and in the opposite direction to the feed of airfurnishedby the conduit 3. In this way the two fluid currents (fuel andair) do not encounter each other. It follows that, on the contrary, thewhole of the fuel is effectively fed to the interior of the chamber 2and cannot enter the conduit 3 whatever the positioning of the conduits3 and 4 relatively to the vertical during flying and even when theaircraft is inverted. Further, by reason of the opposite directions inwhich these two fluid currents enter the chamber 2, the regular andhomogeneous mixing of the fuel and of the air is facilitated.

'I'he said chamber 2 communicates by passages 6 (orifices or pipes) ofrelatively small section and more or less regularly distributed over thewhole of the surface of the wall of the said chamber 2, with a space lclosed to the outer air and which surrounds the said chamber completely`It follows that whatever the position of the carburetor in space, themixture formed in the chamber 2 can enter the space l by the whole or bycertain of the said passages 6.

The said space `I communicates with a pipe il which feeds the mixtureentering the said space I into the suction pipe I of the engine beyond(or in front of) the throttling member 4.

'Ihe sections of the passages or orifices 6 and 'that of the air pipe 3have, advantageously, such relative values that the suction effect ofthe engine, acting in the chamber 2 by means of the orifices 6, has asubstantially zero value on the 'g` feed of the outlet orifice I of thefuel pipe 5,

so that the pressure in said chamber 2 is practically independent ofthat prevailing in suction pipe I.

The feed of fuel is effected by a head or a pressure, for example bymeans of a fuel pump drawing the fuel from the reservoir and dischargingit-preferably by means of an arrangement adapted to regulate itsdischarge pressure and which will be described below-into feed pipe ofwhich the outlet I0 in the chamber 2 is controlled by a closure devicesuch as a needle I I connected by a suitable transmission I2 to thecontrol mechanism I3 for the principal throttling member 4. Thearrangement is such that the opening and closing of the members I I and4 is effected simultaneously and according to suitable proportions. r

In order to prevent an excess of fuel by a sudden action on the controlI3 when opening the carburetor, it is of value to limit the speed ofopening of the said members II and 4 in such a way as to permit theengine to accelerate before this opening becomes complete.

The rapidity of thisv opening could be limited by a device having adamping action on control I 3. One of the movable members of thiscontrol I3, such as the rod I4 of the needle Il, may be retarded by adash-pot I5 which does not permit a rapid operation of the control I3 inthe direction of opening but, on the conf be constituted by an expansiondevice with a di.

aphragm I6, 'I'he diaphragm'controls van obturator such as an invertedvalve I1 and it is controlled, on the one hand, by the pressure-of thefuel discharged by the pump and, on the other hand, by the action of anopposing spring I8. By this arrangement, well known in itself.

-there may b'e obtained a regulation of the pressure of the fluiddischarged` by the pump 9.

The pressure of the fluid discharged by the expansion device I6 is afunction of the tension of the spring I8. 'I'his tension is adjustableby -a remote control I5 actuated in any suitable manner whereby the saidpressure may be adjusted at every instant to the' momentary work-V ingconditions, such as the quantity of mixture admitted inpthe engine, thetemperaturaM-the pressure or the density of the atmospheric air, in sucha way as thereby to correct the richness of the mixture furnished to theengine as a function of the said conditions.

For the example according to Fig. 2, the fuel is fed in conduit 5 bymeans Vof va volumetric or rotary pump 91, driven by the motor, itsspeed beingat every instant proportional to that of the motor. Pump 31'discharges thus a'volume of fuel practically constant and at a pressure-which is a determined function of the speed of the pump and,consequently, of that of the engine.

Fuel is delivered to pump91by a tank 2l and a. feed conduit 2|.Discharge conduit 5 of said pump is connected to said feed conduit 2| orsaid tank 20 by means of at least one calibrated orice 22 and at leastone return-conduit 23.

'Ihe section of one calibrated orifice is modifled by a needle 24 orequivalent actuated manually or automatically, such as described above,to correct the discharge pressure of the rotary pump 91, in the knownmanner, without 4alter-- ing the speed of rotation of said pump.

For the example according to Fig. 3, a similar arrangement is used butinstead of the volumetric or rotary pump 91, a centrifugal pump 9 isdriven by the engine, the discharge pressure of said pump 92 being4likewise a function of the speed of said engine. In this alternative, areturn-conduit 23 with its needle 24 or the like is equally provided tocorrect the discharge pressure of the pump 92 according to the actualworking conditions.

What I claim is:

1. A fioatless carbureting system for an internal combustion engine,which comprises a suction pipe communicating with said engine, athrottling member in said suction pipe, a chamber, several passages ofsmall area distributed over the whole of the surface of the wall of saidchamber, a conduit enveloping the walls of said chamber andcommunicating with said suction pipe, a large air inlet passage openingin said chamber, means for feeding fuel into said chamber, means forcontrolling the feed of fuel into said chamber, and means for connectingsaid throttling member and said fuel controlling means. Y-

2. A fioatless carbureting system for an internal combustion engine,whichcomprises a suction pipe communicating with said engine, athrottling member in said suction pipe, a spherical chamber, severalsmall passages distributed over the whole ofthe surface of the wall ofsaid chamber, a conduit enveloping the walls of said chamber andcommunicating with said suction pipe, a large air inlet passage openingin said chamber, means for feeding fuel in said chamber, means forcontrolling the feed of fuel into said chamber, and means for connectingsaid throttling member and said fuel controlling means.

3. A floatless carbureting system for an internal combustion engine,which comprises a suction pipe communicating with said engine, athrottle member in said suction pipe, a chamber, 'means for connectingsaid chamber tosaid suction pipe, a large air inlet passage abutting insaid4 chamber, a pump for .feeding fuel in a conduit opening in thecentral part of said chamber in an opposite direction to the entrance ofair by means of said large passage, means vfory controlling vthe feed offuelinto said chamber, and means for connecting said throttling memberand said fuel controlling means.

4. A floatless carbureting system for an internal combustion engine,which comprises a suction pipe communicating with said engine, athrottling member in said suction pipe. a chamber, means for connectingsaid chamber to said suction pipe, a large air inlet passage abutting insaid'chamber, a pump for feeding fuel in a conduit opening in thecentral part of said chamber and in an opposite and offset directionto'.the entrance of air by means of'said large passage, means forcontrolling the feed of fuel into said chamber, andmeans for connectingsaid throttling inember and said fuel controlling means.

tion pipe communicating with said engine, a`

throt'tiing member in said suction pipe, a chamber, means having a smalleffective' area for connecting said chamber to said suction pipe, airinlet )means having a large effective area and opening in said chamber,whereby the pressure in said chamber is substantially independent ofvariations in the suction in said suction pipe, a pump for feeding fuelinto said chamber opening thereinto at a point of substantially maximumcross section, means for controlling the feed of fuel into said chamber,and means operatively connecting said throttling member and said fuelcontrolling-means for simultaneous movement.

6. A oatless carbureting system for an invternal combustion engine,which comprises a suction pipe communicating with said engine, a

throttling member in said suction pipe, a chamber, means having a smalleffective area for connecting said chamber to said suction pipe, airinlet means having across section less thanthat of said chamber butgreater than that of said connecting means andopening in said chamber,whereby the pressure in said chamber is substantially independent ofvariations in the suction in said suction pipe, a pump for feeding fuelinto said chamber opening thereinto, means for controlling the feed offuel into said chamber, and

means operatively connecting said throttling member and said fuelcontrolling means for ,simultaneous movement.

7. Ina device as claimed in claim 5, a conduit connecting said pump tosaid chamber, means in said conduit for controlling the feed of fuelinto V said chamber and controllable means for varying the ow of fuelthrough said conduit, said Vcontrollable means being adapted to occupy aplurality of positions in which it permits different amounts of fuel tolowthrough the conduit, and being operable at varying pump pressures,soA as to correct the discharge pressure .of said pump and thereby thestrength of the fuel-air mixture fed into said suction pipe.

8. In a device as claimed in claim 5, a conduit connecting said pump tosaid chamber, means in said'conduit for controlling the feed of fuelinto said chamber and controllable means for varying the flow of fuelthrough said conduit, said controllable means being adaptedto occupy aplurality of positions in which it permits different amounts of fuel toflow through the conduit, and being operable at varying pump pressures,so as to correct the discharge pressure of said pump and ,thereby thestrength of the fuel-air mixture fed into said suction pipe, saidcontrollable means being independent of the quantity of air admittedinto the said carbureting system.

, MARCEL MENNESSON.

